Last month, Porsche halted sales of its fabulous 911 GT3 when two examples—one in Switzerland and another in Italy—spontaneously combusted. Since, all 785 units delivered in Europe have been grounded. While a solution to the problem hasn’t been found yet, Porsche CEO Matthias Müller told German publication Der Spiegel that the brand is now aware of what the issue is.

“We know what happened,” Müller said, before adding that “we are testing several fixes.” What exactly caused the fires, however, remains a mystery. Porsche won’t comment on the problem, but Müller said that his company would speak in great detail about the issue once a solution has been found. Porsche tells us that GT3 owners will be informed prior to media and the general public.